public key is not a stand alone thing to transfer to someone else. it is the second (and public) part of a duo in the asymmetric cryptography scheme. private and public keys are inseparable so you can only generate a public key from that private key.
This way i can transfer ownershuip a Public Key A using it's priv. key A to the owner of Pubkey B. So the Privkey B owner is also the owner of PubKey A.
even if it was possible you still have to provide a mechanism and some sort of proof (like signatures that are already in use) to prove the ownership change. so there is no difference here.